Air diffuser

ABSTRACT

An air diffuser ( 10 ) is provided which includes a casing ( 12 ), a trim element ( 14 ) that is attachable to the casing ( 12 ) in a spaced configuration and a bracket ( 58 ) for attaching the trim element ( 14 ) to the casing ( 12 ). The bracket ( 58 ) includes first attachment formations ( 66 ) that are attachable to complemental formations ( 74 ) on the trim element ( 14 ) in a locking manner, and second attachment formations ( 68 ) that are attachable to complemental formations on the casing ( 12 ) in a releasably clipping manner. The diffuser ( 10 ) includes a control element ( 16 ) disposed between the casing ( 12 ) and the trim element ( 14 ) and a mechanism ( 38 ) for moving the control element ( 16 ) relative to the casing ( 12 ) and the trim element ( 14 ), wherein the mechanism ( 38 ) is fixedly attached to the trim element ( 14 ), between the trim element ( 14 ) and the control element ( 16 ).

FIELD OF THE INVENTION

This invention relates to air diffuser

BACKGROUND TO THE INVENTION

Air diffusers are used in air conditioning systems to regulate the flow of air from air ducts into habitable spaces such as rooms.

In a typical diffuser, a main casing of the diffuser is installed in place of a ceiling tile in a suspended ceiling and is connected to a duct above the ceiling. A central, fixed trim disc is suspended below the casing and is spaced from the casing and a movable control disc is suspended above the trim disc. Air can flow from a central inlet of the casing, that is connected to the duct, downwardly and around the peripheries of the control disc and trim disc into the room below. The flow of air is controlled by moving the control disc between an open position in which it is close to the top of the trim disc and a closed position, in which it is located higher, close to or against the casing, to block the air flow.

The flow of air can typically be regulated by manual adjustment of the control disc in so-called “constant volume” diffusers. Alternatively, the adjustment of the control disc can be automated by using elements that deform in response to temperature variations or by positioning the control disc with an electric motor.

The trim discs are typically suspended from the casing and are kept sturdy with spaced pillars that extend downwardly from the casing. These pillars are usually visible around the periphery of the trim discs and have been found to be aesthetically unpleasing to some users.

The mechanisms by which the positions of control discs are adjusted are typically suspended from brackets that extend across the inlets of the casings, but the manufacture of these brackets increases the cost of manufacturing the casings. Further, where diffusers include electrical regulating mechanisms, the electrical motors often move up and downwardly with the control discs, causing additional loading on the motors and the motors are usually exposed to the airflow in the diffuser and are thus exposed to extreme temperatures when the air is flowing or immediately after airflow has stopped.

The object of the present invention is to provide an improved air diffuser with a configuration that is aesthetically pleasing, cost effective and functional and that overcomes these and other disadvantages of known diffusers.

BRIEF DESCRIPTION OF THE INVENTION

According to a first aspect of the present invention there is provided an air diffuser comprising a casing, a trim element that is attachable to the casing in a spaced configuration and a bracket for attaching the trim element to the casing, wherein the bracket includes first attachment formations that are attachable to complemental formations on the trim element in a locking manner, and second attachment formations that are attachable to complemental formations on the casing in a releasably clipping manner.

The complemental formations on the trim element may be spaced inwardly from the periphery of the trim element.

The second attachment formations may be configured so that the bracket is attachable to the casing in bayonet fashion. The second attachment formations may be resilient hooks and the complemental formations on the casing may be pairs of apertures, such that each hook formation can grip a bridge extending between each pair of apertures.

According to another aspect of the present invention, there is provided an air diffuser comprising a casing, a trim element that is attachable to the casing in a spaced configuration, a control element disposed between the casing and the trim element, and a mechanism for moving the control element relative to the casing and the trim element, wherein the mechanism is fixedly attached to the trim element, between the trim element and the control element.

The mechanism may include a threaded actuator shaft to which the control element is attached in a threaded manner and the mechanism may be configured to rotate the actuator shaft to displace the control element in a treaded manner.

The mechanism may include a motor and transmission that are attached to the trim element and that are configured to rotate the actuator shaft, which may extend generally perpendicularly relative to the trim element.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of non-limiting example, to the accompanying drawings in which:

FIG. 1 is a cross sectional view of an air diffuser in accordance with the present invention;

FIG. 2 is a three dimensional view of a sub assembly of the diffuser of FIG. 1;

FIG. 3 is an exploded view of the sub assembly of FIG. 2;

FIG. 4 is a three dimensional view of a trim disc of the diffuser of FIG. 1;

FIG. 5 is a three dimensional view of an induction channel of the diffuser of FIG. 1;

FIG. 6 is a three dimensional view of an induction tube of the diffuser of FIG. 1;

FIG. 7 is a three dimensional view of a stepped motor of the diffuser of FIG. 1;

FIG. 8 is a three dimensional view of a motor cap of the diffuser of FIG. 1;

FIG. 9 is a three dimensional view of an actuator shaft of the diffuser of FIG. 1;

FIG. 10 is a three dimensional view of a control disc of the diffuser of FIG. 1;

FIG. 11 is a three dimensional view of a dome for fitting on the control disc of FIG. 10;

FIG. 12 is a three dimensional view of a control disc cap bush of the diffuser of FIG. 1;

FIG. 13 is a three dimensional view of an induction tube guide of the diffuser of FIG. 1;

FIG. 14 is a side elevation of a bayonet clip of the diffuser of FIG. 1;

FIG. 15 is a top plan view of the bayonet clip of FIG. 14.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to the drawings, an air diffuser in accordance with the present invention is generally indicated by reference numeral 10 and includes a casing 12, a trim element in the form of a trim disc 14 spaced from the casing and a control element in the form of a control disc 16, movable between the trim disc and the casing.

The casing 12 defines an inlet 18 that is connectable to a supply duct of an air conditioning system (not shown) and that leads to a recess 20. In use, the casing 12 is mounted in the ceiling of a room and the inlet 18 is connected to the supply duct, so that air flows from the duct, via the inlet, into the recess 20, from where it can flow into the room. The flowing air can be warmer or cooler than the ambient air in the room, depending on the operational mode of the air conditioning system. The operation of the air conditioning system will not be described herein in detail. All that is important for the purposes of the present invention is that the volume of air that flows from the duct, into the room, via the diffuser 10, needs to be controlled.

The remainder of the diffuser 10, apart from the casing 12, is illustrated in FIGS. 2 and 3 and comprise a sub assembly, generally referred to by reference numeral 22.

Referring to FIGS. 2 to 6, the sub assembly 22 includes the trim disc 14 that is mounted at the bottom of the sub assembly and is visible from the room below. It defines a central aperture 24 in which a perforated cap 26 is receivable. The circumferential edges of the trim disc extend upwardly at about 45 degrees. An induction channel 28 is fixedly attached to the top of the trim disc 14 and defines an inner cavity that is open at a central aperture 30, at an offset aperture 32 and at the one end 34 of the channel. An induction tube 36 can be clipped into the offset aperture 32 in an upright orientation so that a short, lower end of the induction tube protrudes downwards into the cavity of the induction channel 28 and the larger upper part of the induction tube stands upright.

In use, some of the air flowing from the inlet 18 flows down the induction tube 36, into the induction channel 28 and out via the open end 34. The flow of air draws ambient air from within the room into the induction channel 28 via the perforations of the cap 26. A room temperature sensor can be mounted in the cap 26 to measure room temperature and will be exposed to a constant flow of air from the room.

Referring to FIGS. 1, 2, 3 and 7 to 9, a mechanism in the form of a geared electric motor, preferably a stepped motor 38, is mounted on top of the induction channel 28 and blocks the central aperture 30, although the motor is not directly, fixedly attached to the induction channel. (The motor 38 is shown upside down in FIG. 7.) The stepped motor 38 includes an internal transmission, connected to a rotatable external protuberance 48 and is covered by a motor cap 40, which defines a central aperture 42 at its top, in which two bearing bushes 44 are receivable. The motor 38 is screwed to the inside of the cap 40, which is in turn clipped to the top of the induction channel 28 into peripheral recesses of the aperture 30.

An actuator shaft 46 is connected to the protuberance 48 of the stepped motor 38 and extends upwardly though the bushes 44 and into the inlet 18/recess 20 of the casing 12. The shaft 46 is positively connected at its lower end to the protuberance 48, to be rotated by the motor 38 through its transmission and is free to rotate within the bushes 44. A helical thread (not shown) is defined on the circumference of the shaft 46.

Referring to FIGS. 2, 3 and 10 to 13, the control disc 16 is generally planar, but has downwardly angled edges around its circumference, at an angle of about 45 degrees. At the centre of the control disc 16, it forms a central aperture 70 into which a hollow control disc cap or dome 50 is clipped. The dome 50 forms part of the control disc 16, so that the space inside the dome 50 is below the control disc. The dome 50 defines a cavity on its inside in which the motor cap 40 is receivable with clearance. In the centre of the dome 50, an aperture 51 is defined in which a control disc bush 52 is attachable with a key that prevents it from rotating. The bush 52 is internally treaded, complemental to the thread of the shaft 46. An offset aperture 54 is defined in the control disc, in which an induction tube guide 56 is receivable, so that the induction tube 36 can pass through the guide, with clearance. Three circumferentially spaced leg apertures 72 are defined in the control disc 16, around the protuberance 50.

Referring to FIGS. 2, 3, 14 and 15, the sub assembly 22 includes a bracket in the form of a bayonet clip 58. The clip 58 has a central ring 60 from which three spaced radial arms 62 extend and from which three generally parallel, spaced legs 64 extend. The spacing of the legs 64 is generally the same as that of the leg apertures 72 in the control disc 16, so that the legs can pass through the leg apertures, with clearance.

At the end of each leg 64 that is remote from the ring 60, there is a first attachment formation in the form of a resilient clip 66 that can clip into a complemental formation in the form of a rectangular aperture 74 formed in the top of the induction channel 28 (see FIG. 5). The clip 66 can only be released from its clipped engagement with the aid of a screwdriver or similar tool, so that it can be regarded as a locking engagement.

At the end of each arm 62, there is a second attachment formation in the form of a resilient hook 68 that is attachable to complemental formations in the form of pairs of apertures defined in the casing 12. The hooks 68 are all disposed on a common radius of the complemental apertures, such that the three hooks can be attached to the apertures simultaneously, in bayonet fashion. However, the hooks 68 and their complemental apertures are shaped such that their attachment to the casing 12 is in a releasable clipping manner.

Referring to FIGS. 2 and 3, in use, the sub-assembly 22 is assembled by fitting the components together as described herein above. In particular, the trim disc 14, induction channel 28, induction tube 36, stepped motor 38, motor cap 40, bushes 44 and shaft 46 are assembled as described herein above and the control disc bush 52 is screwed onto the shaft. The induction tube guide 56 is fitted to the control disc 16 and the control disc is fixedly fitted onto the control disc bush 52, with the induction tube 36 passing through the induction tube guide. The clips 66 and parts of the legs 64 are passed through the leg apertures 72 defined in the control disc 16 and the clips 66 are clipped into locking engagement with the apertures 74 on the induction channel. It is to be appreciated that the order in which the components are assembled, may vary.

The sub assembly 22 is attached to the casing 12, by releaseably clipping the hooks 68 into their complemental apertures defined in the casing 12, in bayonet fashion. This holds the advantage that the casing 12 can be fitted into a ceiling and the entire sub assembly can be assembled and kept apart until construction of the ceiling is complete, before being fitted. All the moving parts of the diffuser 10 are part of the sub assembly 22 and if access to any of these parts is required, this can easily be achieved by removing the sub assembly, in bayonet fashion. Sub assemblies 22 requiring work can also be replaced quickly and easily with other sub assemblies, while the work is being done.

During operation of the diffuser 10, the rate of air flow through the recess 20 is controlled by lifting and lowering the control disc 16, to allow free flow of air around the circumferences of the control disc and the trim disc 14 or by lifting the control disc to obstruct the flow path of air, in part. The lifting and lowering is achieved by the motor 38 rotating the shaft 46 so that the bush 52 is caused to move axially along the shaft, upwardly or downwardly, in threaded fashion. The control disc 16 is attached to the bush 52 and is thus also lifted and lowered. Here the invention holds the advantage that the motor 38 is housed quite low in the diffuser 10, shielded from the extreme temperatures of the flowing air, by the control disc 16 and the motor cap 40. Further, the motor 38 and shaft 46 are not lifted and lowered, themselves, thus reducing the load on the motor.

The motor 38 is powered via electrical wires (not shown) that extend from a source above the ceiling. These wires extend through the apertures in the casing 12 where the hooks 68 are attached and extend along passages defined in the arms 62 and legs 64 of the clip, from where they can extend though any suitable apertures or the like, preferably through the induction channel 28. The wires include at least one releasable connector 76 that allows them to be connected and disconnected quickly and easily when the sub assembly 22 is installed or removed. The connector 76 is shown in FIGS. 1 to 3 and can be received in a suitable recess defined on top of one of the arms 62. In order to ensure that wires that extend from the connector 76 into the ceiling are neatly kept inside the passage defined in the arm 62, two retaining clips 78 can be clipped over the channel, to hold the wires captive within the channel. It should be borne in mind that part of the connector 76 and the wires extending into the ceiling, do not form part of the sub assembly 22, but remain in the ceiling, to be connected to the part of the connector that is permanently fitted on the sub assembly, when the sub assembly is installed in the ceiling.

The clip 58 is preferably made from plastic and in order to avoid the sub assembly 22 from falling in the event of a fire, or other cause for the clip 58 to fail, at least one metal safety wire (not shown) is provided that extends along one arm 62 and one leg 64 and the ends of which engage in the apertures of the induction channel 28 and the casing 12 at the same time as the bayonet fashion attachment of the hooks 68. Even if all the hooks 68 fail, the sub assembly 22 will be prevented from falling by the attachment of the safety wire to the casing 12 and the sub assembly.

The invention holds a number of advantages in addition to those mentioned above. Among these, there is no need for brackets or the like in the inlet 18 that need to be added in costly manufacturing operations and that can restrict air flow. Further, there are no unsightly pillars or other supports that are visible through the gaps around the circumference of the trim disc 14. 

1. An air diffuser comprising a casing, a trim element that is attachable to the casing in a spaced configuration and a bracket for attaching the trim element to the casing, wherein the bracket includes first attachment formations that are attachable to complemental formations on the trim element in a locking manner, and second attachment formations that are attachable to complemental formations on the casing in a releasably clipping manner.
 2. An air diffuser as claimed in claim 1, wherein the complemental formations on the trim element are spaced inwardly from the periphery of the trim element.
 3. An air diffuser as claimed in claim 1, wherein the second attachment formations are configured so that the bracket is attachable to the casing in bayonet fashion.
 4. An air diffuser as claimed in claim 3, wherein the second attachment formations are resilient hooks.
 5. An air diffuser as claimed in claim 4, wherein the complemental formations on the casing are pairs of apertures, such that each hook formation can grip a bridge extending between each pair of apertures.
 6. An air diffuser comprising a casing, a trim element that is attachable to the casing in a spaced configuration, a control element disposed between the casing and the trim element, and a mechanism for moving the control element relative to the casing and the trim element, wherein the mechanism is fixedly attached to the trim element, between the trim element and the control element.
 7. An air diffuser as claimed in claim 6, wherein the mechanism includes a threaded actuator shaft to which the control element is attached in a threaded manner, the mechanism being configured to rotate the actuator shaft to displace the control element in a treaded manner.
 8. An air diffuser as claimed in claim 7, wherein the mechanism includes a motor and transmission that are attached to the trim element and that are configured to rotate the actuator shaft.
 9. An air diffuser as claimed in claim 8, wherein the actuator shaft extends generally perpendicularly relative to the trim element. 